Tail lamp lens



jan. 26, 1954;r

Original Filed Feb. 2l. 1949 H. Q. MEAD ET AL TAIL LAMP LENS 2 Sheets-Sheet l Jan. 26, 11954 H. c. MEAD ET Al. 2,667,572

TAIL. LAMP LENS Original Filed Feb. 2l, 1949 2 Sheets-Sheet 2 p5 @agiyfif/gd Patented Jan. 26, 1954 'rAlL LAMP LENS Howard C. Mead and GeorgeW. Onksen, Jr., Anderson, Ind., assignors to General Motors Corporation,Detroit, Mich., a corporation of Delaware Original application February21, 1949, Serial No. 77,494. Divided and this application March 1, 1950,Serial No. 157,983

1 Claim.

It is an object of the present invention to provide an improvedautomobile tail lamp and fuel tank inlet cover assembly.

It is another object to provide an automobile tail lamp and coverassembly having means to support the assembly in an opening in the bodystructure with an external surface of the lamp forming a continuous partof surface of the body and having a movably mounted lamp housing servingto conceal the fuel tank inlet so it will not detract from thestreamline contour of the body.

Still another object is to provide a tail lamp lens having suitablelight directing characteristics while having an external surfacedesigned to form a part of a continuous streamlined body surface.

Further objects and advantages of the invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize the invention will be pointed out with particularity in theclaim annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to theaccompanying drawings in which Figure l is a View taken along the lineI-l of Figure 2 illustrating the tail lamp and cover assembly embodyingthe present invention mounted in the rear fender of an automobileadjacent the fuel inlet; Figure 2 is a View taken along the line 2 2 ofFigure l Figure 3 is a view taken along the line 3--3 of Figure l;Figure 4 is a partial view in section and partly broken away of the taillamp signalling lens; Figure 5 is a View taken along the line 5 5 ofFigure 4 and Figure 6 is a view taken along the line t-t of Figure 5.

Referring now to the drawings and particularly to Figures l to 3, thereis illustrated a rear portion 2 of an automobile with an opening l ofsufficient size and location to provide convenient access to the fueltank inlet pipe 6. While the opening may be located in any convenientpart of the body structure, it is preferred that the inlet pipe belocated so that access to the pipe is obtained through an opening in thefender structure. A removable cap 3 is provided for closing the inletpipe and its details of construction along with the inlet pipe t beingwell known need not be described here in detail.

Pivotally mounted in the opening t is a housingl IB adapted to house anelectric lamp I2 and provide a cover for the inlet pipe of the fueltank. The housing comprises a lens It and a support I6 to which the lensis attached by threaded 2 members I8; To provide for sealing theinterior of the housing against the admission of water, a gasket 20 isinterposed between the lens and the upwardly extending wall of thesupport.

The support l5 is formed with perpendicularly disposed walls, theexternal edges of which are arched to conform to the fender contoursdened by the opening 4. The upwardly extending wall of the support isprovided with an integral enclosure 22 extending oppositely of thesupported lens i4 in which a, lamp socket 2t is partially recessed. Thelamp socket is mounted in the housing by a bracket 26 which isresiliently secured to the upwardly extending wall of the support onopposite sides of enclosure 22 by threaded members, not shown. Anelectrical circuit to the lamp I2 is established by lead-in Wires 28connected to the terminals of the lamp socket and entering the enclosure22 through a rubber grommet 30 disposed in an aperture 32 in the end ofthe enclosure. The rubber grommet is adapted to be recessed in the cablesheath 3| surrounding the lead-in Wires to prevent the introduction ofmoisture to the interior of the sheath and in addition forms a seal inthe aperture 32 to make the interior of the housing I0 substantiallyWeatherproof. Adjacent the enclosure 22 and offset from the verticalplane bisecting the housing and support, the upwardly extending Wall ofsupport I6 is provided with an aperture 33 in which a light directinglens is positioned. The lens 34 is provided to direct light from thelamp l2 onto the gasoline tank inlet pipe 6 when thepipe is uncoveredand the housing is in the open position. As the lens is offset from thehousing vertical midplane inwhich the source of light from rllament 36of the lamp l2 is located, parallel light bending formations are formedon one surface of the lehs-3ll to bend the light to illuminate the pipe6 when the housing is in the open position. As it is considereddesirable that a lamp adapted to serve as a gasoline inlet cover beprovided With auxiliary signal means when the lamp housing is in theopen position, the support It is provided with an aperture 40 whichpermits light to be directed through the aperture and rearwardly of thelamp when the inlet pipe is uncovered.

The lamp housing l0 is supported in the opening 4 by a frame member 42attached to the inturned fender edges 44 outlining the fender openingil. The frame member 42 is adie casting formed with perpendicularlydisposed arched frames similar in form to the arched walls of support I6and provided with bolt holes 46 for securing the frame to the inturnededges 44 of the fender opening. To provide additional support for theinlet pipe 6 in the fender opening, a support frame 49 welded to theinlet pipe is connected as shown in Figs. l to 3 by an angle bar il tothe frame member 42. To provide for movement of the housing it touncover the inlet pipe '6, the support 16 is pivntally connected to theframe member l2 by a hinge consisting of a connecting link 4S and a pairof parallel connecting links 5l! shown connected respectively at their'opposite ends to a flange 52 attached to the frame member 42 and theenclosure 29. and an ear 54 attached to the support l5. With the hinginglinks connected to the frame member d2 and support I6 in the mannershown and described, the movement of the lamp housing ifi to its openposition is simultaneously outwardly and upwardly of the fender opening.To provide a restraining force for maintaining the housing at theextreme ends of its angular movement an overcenter spring mechanism isconnected between the flange 52 and the parallel hinging links 58'. Themechanism consists of a rod 5S pivotallv connected at one end to theflange 52 and slidably connected at its other end to a yoke bar 58extendingr between the parallel links 5fl. To provide an overcenterspring action, a compressed helical spring. Sil is mounted on the rod 5Sbetween the yoke bar 5d and the point of connection with the ange E2.With the housing 1'n its position illustrated in Figure l the force ofthe spring acts on the yoke bar 53, to rotate the barY links and housingabout the connecting points on thel flange 52 in a clockwise direction.As the housing is moved angularly from its closed position in acounterclockwise direction the direction of force acting on the housingis reversed due to the action of the overcenter mechanism and the forceacts to move the housing counterclockwise to its open position. Inmoving the housing from its open toits closed'position the action of theovercenter mechanism is similar, providing a restraining force againstclockwise movement initially and subsequently a force aiding clockwisemovement to the closed position.

The lampV housing is provided with a striker plate 62 adapted tocooperate with an overcenter latching mechanism to lock the lamp housingin its closed position' or initiate a counterclockwise movement of thehousing when it is desired to uncover the inlet pipe 6. The strikerplate 62 is attached to the support i6 by a threaded member 84. Thelatching mechanism is enclosed in a housing 6G formed integrally withthe frame member i2 and comprises a latch member 58 and a link 'iiiconnected at one end to the latch member 58 and at its opposite end to apush button 'l2 slidably mounted in one end of thehousing 66. The latchmember 68 is provided with a bifurcated end for engaging the strikerYplateand isv pivotally mounted at substantially its midpoint to a pairof arms 'ill extending from the side of `a cover plate 'It attached tothe other endA of the housing SS. To provide an overcenter spring actionfor the latchingmember E8, a pair of springs 'it are connected betweenthe wall of enclosure Sii and the junction of latch member 68 and link1li,

as shown.

With a latching mechanism such as that shown and described, an inwardmovement of the push button 72 is transformed through link 'Eli toimpart. a clockwise rota-ry movement. to iatching member S8 against therestraining forcey of springs 1.8. As the bifurcated end of the.latching member moves clockwise its left-hand arm engages, 011

striker plate forcing the lamp housing upwardly to permit the graspingof the housing edge for further movement to the open position. With acontinuation of the clockwise movement of the latching member the forceof springs i8 is first neutralized and then its direction is reversed toimpart a force aiding clockwise rotation of the latching member untilthe connected end of the member strikes the plate 16 and is stopped. Tomove the housing to its closed position the housing is moved into therecess until the striker plate engages the left-hand' arm of thebifurcated end. Continued movement of the housing to its closed positionrotates the laching member counterclockwise against the restrainingforce of springs 'I8 until the connected end of the latching member ismoved sufficiently to neutralize and reverse the direction of therestraining force. Thereafter the counterclockwise movement of thelatching member is aided by the force of the springs 18 and theright-handv arm of the bifurcated end engages the striker plate forcingthe housing to its closed position. With the housing in the closedposition the force of the springs I8 acts to lock the housing in thisposition.

As illustrated in Figures l to 3 of the drawings the lens lli is formedwith an unsymmetrical shape in the vertical plane and a symmetricalshape in a plane substantially disposed to it or in the horizontal planeso that the external surface of the lens will conform to the contour ofthe fender. In addition, the internal surface contour conforms generallyto the external surface contour. With such surfaces being asymmetricalwith respect to the focal of the lens the lens would not normally act tocoliimate the light rays from the filament source 35 of the lamp and theoptical efficiency of the lamp as a signalling means would beunsatisfactory. Accordingly the lens is formed with a light collimatingarea surrounding the focal axis, see Figure 5, comprising the centraldioptric condensing button Si) and the concentric dioptric condensingrings 32 and 3G.. As seen in the horizontal section in Figure 6 thelight collimating area comprises two curved surfaces formed aboutdifferent centers, one on each side of the vertical axis of the lens sothat the inner surface of the light collimating area will be in dioptricagreement with the particular curve of the external surface formed atthe nose of the lens. As seen in the vertical section in Figure i theinternal surface of the light collimating area isformed on differentradii along the vertical axis of the lens so that the surface will alsobe in dioptric agreement with the vertical projection of theunsyrnmetrical external surface.' While the surfaces of the rings 82 andat are stepped with. respect to the central button 8d it will beunderstood that they are formed in this manner because the sectionl ofthe lens does not permit the forming of an unbrokensurface. Surroundingthe light collimating area the internal surface of the lens it is formedwith horizontal flutes 86 which diffuse light from the lamp source andare primarily for decoration purposes.

The internalk surfaces of thelens lil is formed by a male plungerprovided with a removable plug having its exposed end formed to mold thelight collimating surface hereinabove described. In this connection theplug comprises a pair of concentric cylinders adapted to form the rings82 and 8d and a central concentric plug' adapted to form the button 8B.

The internal surface of the lens it which is formed by the male plunger,the pair of concentric cylinders, and the central concentric plug,comprises draft surfaces 8l and 83 along the upper and lower walls ofthe body comprising the lens lll, the parallel horizontal uted surfacesS6, the light collimating surfaces 84, 82 and Si) and the continuousannular surfaces 89 and @i joining the light collimating surfacesreferred to. The draft surfaces 81 and 88 are formed by slightlytapering upper and lower parts of the male plunger while the draftsurfaces 89 and Si are formed by continuous parts of the exteriorsurfaces of the concentric plug and the inner one of the concentriccylinders adjacent the extreme outer ends of the plug and innerconcentric cylinder. The surfaces Sli, 82 and 80 are formed by theextreme outer ends of the outer and inner concentric cylinders andconcentric plug, all respectively. All of the draft surfaces referred toare formed around the focal axis of the lens fil) in such manner thatthe plunger, the `concentric cylinders and the concentric plug can bewithdrawn from the transparent body forming the lens Hl.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adapted, all coming within the scope of the claim whichfollows.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

A lens body comprising an external surm face which is asymmetrical withrespect to a focal axis in a vertical plane through said lens and axis,and an inner surface which is formed by a plurality of continuouslycurved light collimating surfaces concentrically disposed about saidaxis and by continuously curved annular connecting surface means, eachof said plurality of curved surfaces being formed by surface elementsintersecting said axis at different places along said axis, each of saidcurved surfaces ha ing Varying radii of curvature relative to the focalaxis, a centrallyT disposed button surrounded by said continuouslycurved surface means and said annular connecting surface means, saidannular connecting surface means being formed between said plurality ofsurfaces and having the surface elements thereof extending substantiallyin parallel relation to said focal axis, said plurality of curvedsurfaces and and said external surface being in dioptric agreement tocollimate light from a point source on said focal axis.

HOWARD C. MEAD. GEGRGE W. ONKSEN, J n.

References Cited in the le of-this patent UNITED STATES PATENTS NumberName Date D. 112,463 Levy i Dec. 6, 1938 1,955,597 Lamblin-Parent Apr.17, 1934 2,328,329 Dickson Aug. 31, 1943

